1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Rick Macklem at The University of Guelph.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/param.h>
36#include <sys/syslog.h>
37#include <sys/wait.h>
38#include <sys/linker.h>
39#include <sys/mount.h>
40#include <sys/sysctl.h>
41
42#include <err.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <unistd.h>
46
47#define	MAXNFSDCNT      20
48
49static void
50usage(void)
51{
52	(void)fprintf(stderr, "usage: nfsiod [-n num_servers]\n");
53	exit(1);
54}
55
56int
57main(int argc, char *argv[])
58{
59	int ch;
60	struct xvfsconf vfc;
61	int error;
62	unsigned int iodmin, iodmax, num_servers;
63	size_t len;
64
65	error = getvfsbyname("nfs", &vfc);
66	if (error) {
67		if (kldload("nfs") == -1)
68			err(1, "kldload(nfs)");
69		error = getvfsbyname("nfs", &vfc);
70	}
71	if (error)
72		errx(1, "NFS support is not available in the running kernel");
73
74	num_servers = 0;
75	while ((ch = getopt(argc, argv, "n:")) != -1)
76		switch (ch) {
77		case 'n':
78			num_servers = atoi(optarg);
79			if (num_servers < 1) {
80				warnx("nfsiod count %u; reset to %d",
81				    num_servers, 1);
82				num_servers = 1;
83			}
84			if (num_servers > MAXNFSDCNT) {
85				warnx("nfsiod count %u; reset to %d",
86				    num_servers, MAXNFSDCNT);
87				num_servers = MAXNFSDCNT;
88			}
89			break;
90		case '?':
91		default:
92			usage();
93		}
94	argc -= optind;
95	argv += optind;
96
97	if (argc > 0)
98		usage();
99
100	len = sizeof iodmin;
101	error = sysctlbyname("vfs.nfs.iodmin", &iodmin, &len, NULL, 0);
102	if (error < 0)
103		err(1, "sysctlbyname(\"vfs.nfs.iodmin\")");
104	len = sizeof iodmax;
105	error = sysctlbyname("vfs.nfs.iodmax", &iodmax, &len, NULL, 0);
106	if (error < 0)
107		err(1, "sysctlbyname(\"vfs.nfs.iodmax\")");
108	if (num_servers == 0) {		/* no change */
109		printf("vfs.nfs.iodmin=%u\nvfs.nfs.iodmax=%u\n",
110		    iodmin, iodmax);
111		exit(0);
112	}
113	/* Catch the case where we're lowering num_servers below iodmin */
114	if (iodmin > num_servers) {
115		iodmin = num_servers;
116		error = sysctlbyname("vfs.nfs.iodmin", NULL, 0, &iodmin,
117		    sizeof iodmin);
118		if (error < 0)
119			err(1, "sysctlbyname(\"vfs.nfs.iodmin\")");
120	}
121	iodmax = num_servers;
122	error = sysctlbyname("vfs.nfs.iodmax", NULL, 0, &iodmax, sizeof iodmax);
123	if (error < 0)
124		err(1, "sysctlbyname(\"vfs.nfs.iodmax\")");
125	exit (0);
126}
127
128